How does the 9th District court have juridiction over internationl waters?
I understand the Japanese brought suit against Paul Watson and his Sea Shepherd Society and their home base is Friday Harbor in the Seattle area.
Piracy on the high seas can be punished by any country, under an old legal doctrine called "universal jurisdiction." The doctrine goes back to Roman law, under which pirates were considered hostes humani generis, enemies of the entire human race.
US Constitution, Article I, Section 8:
"To define and punish Piracies and Felonies committed on the high Seas, and Offences against the Law of Nations;"
Congress defined "piracy" and the Courts are simply upholding this Constitutional law and power.